Submarine mine



-Ap v6, 1948. 1 c. N. HICKMAN Vsummum@ MINE original Filed Nov. 13k, 1924 Patented Apr. 6, l1948 UNI-TED ,STATES MTI-:1yr oFFlcE SUBMARINE MINE Clarence `N. Hickman, Washington, D. C., assignor tothe United States of America as represented by the Secretary of the Navy Application November 13, 1924, Serial No. 749,644

This invention relates to improvements in submarine mines and moref particularly in self-calibrating devices for whatare generally known as drifting mines or pursuitfmines, that is, a ship being pursued drops a number of mines in its wake which comev to restat a predetermined distance below the surface of the'water and occupy that suspended position to be engaged by the pursuing vessels. l f f One of the objects of the present-invention is to provide an improved mine of the above character which will be self-calibrating, that is, come automatically to a position of rest at a predetermined distance below the surface of the water.

A further object is to provide a mine of the above general character -withva' self-calibrating device which may be inexpensivelyV manufactured and installed on standardequipment without material modification of existing parts.

Other objects will be in .part obvious and in part hereinafter pointedf-out in connection with the accompanyin'gsheetfof drawing illustrating one of various possible embodiments of the' present invention.

In this drawing,

Figure 1 is a sectional, elevational view of such parts of the calibrating. device and mine casing as are necessary to understand the invention.

Figure 2 is a side elevational viewvof a portionv kof the device and; I Y l Fig-ure 3 is a detail view of one of the discs.

Referring now to Figure 1, I indicates the mine case which is of usual spherical `construction adapted to contain* a liringA mechanism and an explosive charge, these parts being of such wellknown construction and installation that a description or detailed statement is believed to be unnecessary. .fr

Within this mine casingris a main support 2 for the internal mechanism of the' Calibrating device,this part being screwed up against the mine case as shown and provided with a rubber gasket Sand lock. nut 4. A bracket 5 on the exterior ofthe ,mine casel is adapted to support the detachable weights, will be hereinafter more fully explained. Within the mine case is a cylinder Ii adapted to be clamped against the member 2-by means of a collar-1. One end of a ilexible rubber sleeve 9 is folded back upon itself around a brass ring 8 as shown and makes a water tight joint between the parts 2 and 6 and at the same time forms a means for securing one end of this sleeve 9. At the end of the cylinder is a cap I0 containing three guide rollers II for supporting a movable rod .23 extending through the cylinder as shown. Surrounding this rod 23 is a member I2 acting as a support for one end of the spring I3 while at the opposite end is a similar support I4 for a similar spring I3. This part I4 is adaptedrto screw onto a member I5 which takes up against the internal tube I6 and clamps the other end of the rubber sleeve 9 wrapped around its supporting ring I1. The part I5 also supports the rod 23 as well as an extension thereof or rod 24 which is supported by rollers 20 which act as guides for the rod 24 and its extension 25. A pin I8 protrudes from the part 2V and acts as a lock to prevent the member I5 from turning while tightening up the rod 25 by means of 'its threaded engagement with the rod 24. The two guides 21 secured to the bracket 5 are provided with spacers adapted to hold discs 26 in their proper position, the rod 25 keeping the discs from dropping oif until the desired time.

In Figure 2 there is shown a plan View o-f the disc weights and,

Figure 3 is a detailed View of one of the disc weights. Piece 2l acts as a support for the springs I3 and carries guide rollers 22.

It ywill be noted from these drawings that the lower support 21 engages a notch 28 and as the pin 25 is withdrawn from the hole 3U, Figure 3, then the disc is freevto roll in the direction of the arrow, Figure 2, and drop from the lower support 21.

Inoperation when the mine is planted or rcleased from the pursued ship, for example, it sinks until the external water pressure is suiiicient to overcome the initial tension of the springs I3. (This should be adjusted to approximately feet.) When the mine reaches this depth the moving piston I5 begins to compress the springs I3, moving inward and pulling the rod 25 with it. As soon as it has moved about .3 inch the first weight` is permitted to drop off. In like manner for each .3 inch motion of the piston it drops ione of the disc weights. This continues until a suicient number of discs have been dropped to properly calibrate the mine. When the mine begins to rise the springs I3 push the piston out which in turn pushes the rod 25 back to its originalvposition thus retaining the remaining disc weights. Ifffor any reason, the mine should Vbecome heavy due to leakage vor water absorbed by the floats, it will again sink until it .has dropped oif weights enough to again properly calibrate itself.

In other words the principle upon which this mechanism operates is as follows: The mine, together with the attached device is planted in the usual manner. The negative buoyancy of the system is supposed to have been adjusted to approximately ten pounds. The mine sinks until has negative buoyancy. After having dropped the Weight which changes the negative buoyancy of the system to a positive buoyancy, the system .slowly rises until the top buoy reaches thev sur- 4 with and actuating said rod and adapted to be moved on increase of hydrostatic pressure, and spring means reacting upon said piston for restoring the rod to normal position should the mine come to the surface.

3. In combination with a mine casing, a plurality of detachable weights externally mounted thereon, efretreetable rad spending-.through the casing andsengaging withthe weights, and a piston subjected to hydro-pressure connected with the rod for progressively disengaging the latter It will thus be seen -that it is not necessary to Z have a top buoy with a positive buoyancy of more than about three pounds. A buoy of this type made ofA cork` needbe.. no more than five Vinches in diameter and about i'lve inches long. ft-would be ,extremelydicult if possible, to locate a buoy of this .sizeunder usualservice conditions. In additionto thisgreat advantage, that is, making it unnecessaryto use a large buoy on the surface, a mine equipped with such a self-calibratingdevice willl adapt itself to sea-water of most. any density and temperature.

- It. is fexceedinglydiicultto load a large number of. mines so that they will have exactly the samebuoyancy. The use yof such a self-calibrating device would makev it unnecessary to load thevminewith such a high degree of accuracy. The self-Calibrating device herein described contains ten two-pound Weights. If, in loading theminesan attempt is made to obtain a negative. buoyancy of ten pounds, it will calibrate itself' correctly-evenifl there is an error of ten poundsin the adjustment, either light or heavy. 'Ihis gives a total possible variation in the weights of the minesof twenty pounds. Ii it is so desired, a greater number of Vweights may be used.

This will increase the possible errors in the calibration orvv the variations in buoyancy due to the salinity and temperature of the Isea-water.

It will thusbe seen that the present invention comprehends a simple and practical self-calibrating device fordrifting mines which may be inexpensively manufactured, assembled and installed on standard mine equipment without material modifications or interfering in any Way with the mine explosive charge or the firing mechanism therefor.

What I claim is:

l. In combination with a mine casing, a plurality of detachable weights pivotally supported on the exterior-of the mine, a rod supporting said weights, and a piston within the casing subjectedhto hydrostatic .pressure and actuating the rod wherebyfas saidpiston moves, on increase of hydrostatic pressure, the rod will be retracted to progressively release the weights until a substantial stateof equilibrium is reached.

2. In combination with a mine casing, a vplurality of detachable weights pivotally supported externally thereof, each of salidweights being apertured, a rod passing through the apertures, a hydrostatic piston Within :theimine connected from t the weights upon increased hydrostatic pressure on the former.

4. IIn.combinationwitl'i a mine easing, a plurality -ofdetachable ,weights externally mounted thereon, each ofv said weights being apertured, a cylinderwithimthe,casing, a piston subjected to hydrostatic pressure operable within the cylinder, a' rod'connected to and movable with the piston, said rod passing through the apertures and progressively.disengaging'; themr .when the .piston is moved. by .ir11ea-sed'l budrorstatic tpressure thereupon, vand meansfplsrestorngthapiston and rod t0 normal"epositionawhen.;the pressure is decreased.

5. In. asubmarine drifting mine. .combination, a casing,.,a,reducible.Melgllitcomposed of a plurality .of individual units-each.. piyotally supported exteriorly of the casing, andehydmstatically controlled.':means` for- .progressively releasing said4 units in.A accordancelwitn the, depth ,of lthe YI'llIle.

6. In a submarinemine, v.a casing, aiplurality of weightsdetachablyfsupported.exteriorlyoi the casing, aretractablerod carrying each. `of 4the Weights, and-a hydrostatidmeans. for.. retracting the rod to .releasetheyveights progressively.

7. In a. submarineL minefya, casing, .,a, plurality of weights detachably.. supported. 4onf-the yexterior of the casing, .a vretractable rod carry-ingeach of the weights, and a. hydrostaticmeans. for. retracting the rod toreleaseltheoweights,

8. In a submarineimine, a-casing,` arod-v retractable through the casing, a. .plurality .of weights each carried by and .supported onfthe rod exteriorly.. .ofi the.,m'ine.. casing, Av.and hydrostatic meanstogretract: thefrod. for progressively reducing the -number..-.of-.weights.

9. In a submarinemine, Vavcasing, a plurality of weights, each Weight eccentrica-Hy .supported on the exterior. of i the.. casing labout the same ,axis, and hydrostat'icinea'ns f for progressively.. reducing theA numbergohw'eights.

CLARENCE-.No.HICKMAN.

REFEBENQES GTrED The following references are of reqrdinthe fue of figuraient 

